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Biomedical subjects

J W Hou

Publications and source records attributed to J W Hou.

At least 37 records · Page 2Linked to original sources
PubMed1997

Microdeletion oe chromosomal region 7Q11.23 in Williams syndrome.

We report two children with typical Williams syndrome facial appearance, growth deficiency and developmental delay. Both had supravalvular aortic stenosis (SVAS) and peripheral pulmonary stenosis (PPS), but no hypercalcemia. Chromosomal study in the first case, a 40-day-old girl, revealed a cytogenetically visible proximal interstitial deletion of the 7q11.22-11.23 segment. Another patient, a 3-year-old boy, with a normal karyotype, had milder phenotype with spontaneous remission of SVAS and PPS. Both patients showed allelic loss of the elastin (ELN) gene, exhibiting a submicroscopic deletion at 7q11.23, which was detected by fluorescence in situ hybridization (FISH). The results support the usefulness of FISH for detection of ELN gene deletion as an initial diagnostic assay for patients with SVAS or Williams syndrome. To our knowledge, these are the first cases of Williams syndrome in Taiwanese patients to be proven clinically, cytogenetically and by molecular analysis.

Chromosome Deletion↗
PubMed1997

Tricho-rhino-phalangeal syndrome type II associated with epiglottic aplasia and congenital nephrotic syndrome.

A male neonate with tricho-rhino-phalangeal syndrome type II (Langer-Giedion syndrome) and interstitial deletion of chromosome 8 with karyotype 46, XY, del (8) (q24.11-->q24.13) is reported. In addition to hypotrichosis of the scalp hair, abnormally bulbous nose and redundant skin, which are usually found in this syndrome, aplasia of the epiglottis and non-Finnish type congenital nephrotic syndrome were also present. He died of renal failure and respiratory failure at 11 days of age. Electron microscopy of renal necropsy showed foot process loss, focal thickening and splitting of the glomerular basement membrane and mesangial expansion. These have never been reported and could be new associations in this disease that may serve to support the concept of contiguous gene syndrome in patients with tricho-rhino-phalangeal syndrome.

Epiglottis↗
PubMed1997

CATCH 22: deletion of locus 22q11 in velocardiofacial syndrome, DiGeorge anomaly, and nonsyndromic conotruncal defects.

DiGeorge anomaly (DGA) and velocardiofacial syndrome (VCFS) are frequently associated with monosomy of chromosomal subband 22q11. It is not clear whether individuals who present with only some of the features (e.g., isolated hypoparathyroidism or conotruncal defects) of these conditions also have the same deletion. In a prospective study of 30 children from 1994 to 1996, we used both high-resolution banding and fluorescence in situ hybridization (FISH) to assess the deletion status of children with a wide range of DGA-like or VCFS-like clinical features. Microdeletion of the chromosomal subband 22q11.22 was detected in 17 children by high-resolution banding and in two additional children with conotruncal defect (CTD) who had submicroscopic deletions proved by FISH analyses. Of the patients with microscopical deletion (n = 17), only six had classical DGA (n = 4) or VCFS (n = 2) phenotypes. The other 11 had various forms of congenital heart defects as the only presenting signs of deletion. One patient with DGA stigmata had another chromosomal aberration of monosomy 10p13. Only 10 patients were found to have neither cytogenetic nor molecular abnormalities. Therefore, it appeared that the majority, if not all, of the DGA and VCFS patients with the 22q11 deletion were identifiable using FISH with the single N25 (D22S75) probe. It would also be advisable that children with isolated CTD should be carefully examined to detect the other morphologic abnormalities of DGA and VCFS, or CATCH 22 (cardiac defects, abnormal facies, thymic hypoplasia/aplasia, cleft palate, hypocalcemia, and 22q11 deletion). Once these abnormalities are found, a molecular cytogenetic analysis for the so-called 22q11 region is indicated. Because of other associated chromosomal findings, routine or high-resolution cytogenetic analysis should be performed on patients with suspected CATCH 22.

Abnormalities, Multiple↗
PubMed1997

Partial DiGeorge anomaly associated with 10p deletion.

We report a girl with partial DiGeorge anomaly associated with a distal chromosome 10p deletion. The initial manifestation was hypocalcemia convulsion at the age of 14 days. The patient was small for her gestational age and showed symptoms of poor feeding and inspiratory stridor. Facial dysmorphisms included a cupped ear, hypertelorism downslanted and short palpebral fissures frontal bossing, anteverted nostrils, a flat nasal bridge, and micrognathia. Developmental delay was also noted. Hypoplasia of the thymus was detected by ultrasound examination, but results of immunologic studies were all normal at 6 weeks of age. The echocardiogram, brain ultrasound, electroencephalogram, and magnetic resonance images of the brain were normal, but brainstem auditory evoked potentials showed bilateral sensorineural hearing loss. Chromosomal analysis showed 16, XX, del(10)(p12.3); the parents had normal karyotypes. After treatment with vitamin D, calcium gluconate, and magnesium sulfate, the patient's serum calcium and magnesium levels were within normal limits. She was discharged and received regular follow-up at our clinic for physical therapy and to ensure adequate supply of divalent cations. Complex partial seizure was noted at the age of 1 year and was controlled with carbamazepine. To our knowledge, this is the first Taiwanese reported to have partial DiGeorge anomaly associated with 10p deletion. We recommend that standard karyotyping should be performed in children suspected to have this anomaly.

Chromosome Deletion↗
PubMed1996

Two-peak kinetic curve of the chemiluminescence in phorbol-induced macrophage.

Phorbol-1,2-myristate-1,3-acetate can induce rat macrophage to emit chemiluminescence. The kinetic curve of the chemiluminescence clearly showed two peaks when a proper ratio of phorbol-1,2-myristate-1,3-acetate and macrophage were mixed. It was proved that the first one mainly came from the oxygen free radicals and the second one from NO generated in the phorbol-1,2-myristate-1,3-acetate stimulated cells by using the substitute and inhibitor of NO synthase.

Animals↗
PubMed1996

Studies on nitric oxide free radicals generated from polymorphonuclear leukocytes (PMN) stimulated by phorbol myristate acetate (PMA).

The interaction of NO and O2- free radicals generated from PMA (phorbol myristate acetate)-stimulated PMN (polymorphonuclear leukocytes) was studied by a nitroxide spin trap, DMPO (5,5-dimethyl-1-pyrroline-1-oxide). It was found that addition of L-arginine to the system would significantly decrease the trapped O2- by DMPO and addition of NG-monomethyl-arginine (NGMA) would significantly increase the trapped O2- by DMPO. It was proved that the formation of ONOO- by the reaction of NO and O2- was the main reason for the decrease of trapped O2- in the experiment with xanthine/xanthine oxidase and irradiation of riboflavin systems. The yield of NO during this process was calculated. The generation dynamic of NO was studied by a luminol-dependent chemiluminescence technique and it was found that after stimulation of PMN by PMA, there would be an immediate, significant chemiluminescence, which came mainly from the active oxygen free radicals generated by PMN. If L-arginine was added to this system, the chemiluminescence would increase about 100-fold, but NGMA inhibited the increase of the chemiluminescence. Ten minutes after addition of L-arginine, this increase did not change, the chemiluminescence peak decreased gradually, but the half life increased. The ESR and chemiluminescence properties of NO and ONOO- synthesized were also studied in model systems.

Arginine↗
PubMed1996

Homocystinuria presenting as fatal common carotid artery occlusion.

A patient with homocystinuria presenting with fatal cerebral infarction that resulted from left common carotid artery occlusion is reported. This 13-year-old, healthy and intelligent girl presented with progressive cerebral infarction. Angiography revealed total occlusion of the left common carotid artery and stenosis of the right common carotid artery. Distal stenosis of bilateral vertebral arteries was also observed. Initially Takayasu arteritis with unusual manifestation was considered. However, later investigations revealed homocystinuria was the underlying cause. The sudden onset of fatal stroke as the initial clinical presentation of homocystinuria, as observed in this previous healthy teenager, is noteworthy. We suggest metabolic screening for homocystinuria when treating a patient with unusual vascular lesions.

Adolescent↗
PubMed1996

Metabolic function and liver histopathology in Reye-like illnesses.

Forty children with Reye syndrome (RS) or Reye-like illnesses were investigated to elucidate the underlying aetiologies. Extensive biochemical studies including patterns of organic acids and amino acids, liver histopathology, and, if available, a DNA approach were performed. In addition to classical RS (n = 10), the causes of Reye-like conditions included hereditary organic acidaemias (n = 13), urea cycle defects (n = 4), mitochondrial disorders (n = 3), fulminant hepatitis (n = 2), tyrosinaemia (n = 1), valproate-associated hepatotoxicity (n = 1), and other non-specific generalized organic acid disorders (n = 6). It is important to collect specimens when encephalopathy with liver dysfunction of unknown causes is noted. When the underlying inherited metabolic disorders are confirmed, the prevention of the recurrence by adequate diet control and medications, and genetic counselling become possible.

Acidosis↗
PubMed1996

Amelia, dextrocardia, asplenia, and congenital short bowel in deleted ring chromosome 4.

We report a female baby with multiple congenital anomalies including left upper amelia, congenital short bowel with malrotation and pseudo-obstruction, dextrocardia with situs solitus, patent ductus arteriosus, and a tiny atrophic spleen. Chromosome study showed de novo 46,XX/46,XX,-4, + r(4)(p16-->q22.3)/47,XX,4, + r(4) (p16-->q22.3), + del(4)(pter-->q22.3:). The clinical findings in the patient were probably caused by the interaction of partial trisomy 4pter-->q22.3 or 4p16-->q22.3 and partial monosomy of 4q22.3-->4qter. This karyotype and phenotype have not previously been reported.

Abnormalities, Multiple↗
PubMed1996

Kleine-Levin syndrome in a boy with Prader-Willi syndrome.

A 9 1/2-year-old Taiwanese boy with Prader-Willi syndrome had the following characteristics: difficulties with sucking, feeding and hypotonia during infancy, a dysmorphic face (triangular mouth, high arched palate, almond-shaped eyes and large head circumference with a relatively narrow bifrontal diameter), borderline intelligence, hypogonadism, hyperphagia, skin picking and truncal obesity. The boy experienced two hypersomnia episodes, at age 8 and 9 years, with both episodes lasting for 10 days. During the two episodes, he was found to have an exacerbated case of hyperphagia, pica, poor emotional control, stereotyped speech and agitated behavior upon awakening. After each episode, the boy had complete remission. Our findings show that the two episodes are compatible with Kleine-Levin syndrome. The relationship between the two syndromes, the Prader-Willi syndrome and the Kleine-Levin syndrome, deserves further study.

Child↗
PubMed1996

Scavenging effects of salvia miltiorrhiza on free radicals and its protection for myocardial mitochondrial membranes from ischemia-reperfusion injury.

Using low temperature electron spin resonance (ESR) technique, we found that Salvia miltiorrhiza injection could scavenge the oxygen free radicals generated from ischemia-reperfusion injury in the myocardium as effectively as SOD. Using ESR spin trapping technique we found that one of its effective components, Danshensu, could scavenge superoxide anion free radicals generated from the reaction system of xanthine and xanthine oxidase, and that lipid free radicals generated from lipid peroxidation of myocardial mitochondrial membranes could be scavenged by another effective component, Tanshinone. The membrane fluidity of the mitochondria isolated from the ischemia-reperfused hearts was studied with the ESR spin labelling technique, and the TBA-method was used to detect the lipid peroxidation. It was found that Danshensu could protect the mitochondrial membrane from the ischemia-reperfusion injury and lipid peroxidation.

Abietanes↗
PubMed1996

Prader-Willi syndrome: clinical and molecular cytogenetic investigations.

Prader-Willi syndrome is characterized by hypotonia and feeding difficulties in the neonatal period, with the childhood development of hyperphagia leading to obesity, developmental delay, hypogonadism, short stature and small hands and feet. Correct diagnosis of Prader-Willi syndrome is important because of its clinical implications and the need for family genetic counseling. In order to determine the most efficient method of diagnosing the condition, we evaluated 37 patients with a putative diagnosis of Prader-Willi syndrome by both clinical and molecular cytogenetic analyses. Clinical evaluation showed that 25 patients fulfilled the diagnostic criteria for Prader-Willi syndrome. A deletion of the region 15q11.2-13 was cytogenetically identified in 20 patients using a high-resolution technique. Four additional cases were detected by fluorescence in situ hybridization (FISH) with the cosmid probes for D15S11, r-aminobutyric acid receptor beta 3 (GABRB3), small nuclear ribonucleoprotein-associated peptide N (SNRPN) or D15S10 (Prader-Willi/ Angelman syndrome region probes). The deletion of SNRPN was documented in 24 Prader-Willi syndrome patients. Only one additional patient with typical Prader-Willi syndrome features did not have any deletion over 15q11-13 at either the cytogenetic or molecular level. FISH provides a more reliable method than high-resolution chromosome analysis for the diagnosis of Prader-Willi syndrome. Associated conditions such as hypopigmentation, small-joint laxity, arachnodactyly, seizure disorder, optic atrophy, congenital heart disease, Perthes' disease, hirsutism, astigmatism/amblyopia, microcephaly and neuropsychiatric disturbances dictate the effects of a contiguous gene syndrome. Morbidity is high among patients with obesity and associated conditions. Appropriate genetic counseling should be given to the parents and dietary management should be helpful for patients with Prader-Willi syndrome.

Adolescent↗
PubMed1996

Chromosomal rearrangements detected by FISH and G-banding.

Fluorescence in situ hybridization (FISH) using chromosome-specific DNA libraries as painting probes, locus-specific unique sequence (cosmid) probes, and Y-specific repetitive sequences was applied in the analysis of eighteen cases of chromosomal rearrangements of undetermined nature. FISH clarified the origin of the extra or translocated chromosome segments in seventeen patients, one with 2q+, two with 4q+, one each with 6p+, 7p+, 9q+, 10p+, 11q+ and 12p+, two with 13q+, and one each with 15q+, 17p+, 18p+, 20p+, 21p+ and Yq+, as well as the nature of a de novo supernumerary chromosome marker in a previously reported case. By G-banding and molecular cytogenetic studies of the family members, six cases were determined to have unbalanced translocations inherited from the carrier parent. The extra translocated genetic material may cause specific trisomic syndromes, including partial 6p21.3-p23, 9q32-q34.3, 13q32-q34, 15q24-q26, and 17p11.2-p13 trisomies in those patients. A translocated 21q segment on 12p was shown by a painting probe in a patient with Down features. A patient with cat cry syndrome resulting from a loss of the terminal segment of the short arm of chromosome 5 was confirmed by a cosmid probe showing de novo reciprocal translocation between chromosomes 5 and 18:t(5;18) (p13.3;p11.31). With FISH, the extra material on the rearranged chromosome could also be identified as duplicated or translocated. The FISH technique thus provides a method for the analysis of extra structurally abnormal chromosomes (especially in de novo cases), recognizable syndromes (contiguous gene syndromes) caused by translocated deletion from parental balanced chromosome rearrangements, and supernumerary marker chromosomes. FISH subsequent to G-banding is also of great help in the confirmation of preliminary abnormal G-banded karyotypes after a modified destaining procedure. In conclusion, the combination of G-banding and FISH is very useful in the accurate diagnosis of chromosomal rearrangements.

Chromosome Aberrations↗
PubMed1996

Double aneuploidy with Down's-Klinefelter's syndrome.

The occurrence of double aneuploidy, ie, the existence of two chromosomal abnormalities in the same individual, is a relatively rare phenomenon. A 1-year-old boy with Down's syndrome resulting from de novo mosaic 21 trisomy with an additional X in the karyotype: 47,XXY/48,XXY,+21 (4%/96%) is reported. Besides the typical features of Down's syndrome, the patient did not have the commonly associated conditions (recurrent respiratory tract infections, congenital heart disease, thyroid or digestive tract problems). A molecular cytogenetic method with biotin-labeled probe D13Z1/D21Z1 was used to confirm the diagnosis and to clarify the status of Down's syndrome mosaicism which explained the milder stigmata of Down's syndrome in this case. The coexistence of Klinefelter's syndrome (47,XXY) also may have contributed to the development of normal height and micropenis in this patient. To our knowledge, this is the first case of Down's syndrome together with Klinefelter's syndrome in Taiwan.

Aneuploidy↗
PubMed1996

Amino acid and DNA analyses in a family with ornithine transcarbamylase deficiency.

Ornithine transcarbamylase (OTC) is a hepatic mitochondrial enzyme involved in the detoxification of ammonia by the urea cycle. OTC deficiency is an X-linked genetic disorder, usually causing neonatal or infantile hyperammonemia, coma and death. We attended a male newborn who had poor feeding since 30 hours of age, at which time, he then rapidly progressed to a comatose state. Hyperammonemia and liver dysfunction were noted. Analysis of plasma amino acids showed elevated levels of glutamine and alanine, but a decreased level of arginine and no citrulline. OTC deficiency was diagnosed by family history of early death of newborn males on the maternal side and characteristic biochemical findings. In addition, it was proved by Southern blot analysis of genomic DNA. Although OTC deficiency has been described as the most common inborn error of ureagenesis in humans, to our knowledge, this is the first report in a Chinese family confirmed by biochemical and DNA analyses.

Amino Acid Metabolism, Inborn Errors↗
PubMed1995

Galloway-Mowat syndrome in Taiwan.

We report on two Chinese female infants with multiple congenital anomalies: microcephaly, apparent porencephaly or encephalomalacia, developmental delay, minor facial anomalies, and contractural arachnodactyly. In the first patient, focal glomerulosclerosis was diagnosed histologically by percutaneous renal biopsy due to proteinuria with hematuria. Congenital hypothyroidism presenting with markedly low T3 and T4 was also noted. She died at age 5 months. The second patient had a very similar condition but less severe brain and kidney malformations. A variant of Galloway-Mowat syndrome is suspected.

Abnormalities, Multiple↗